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Do we see the future through telescopes? or the past?

  1. Jun 5, 2010 #1
    If a star 100 light years away from Earth exploded this very second, we would only see the explosion 100 years from now.

    If this is true, and if we pointed a telescope at that star right now itself, would we then be able to see it explode right away or would it still take us 100 years to see the explosion even with the most powerful telescope?
  2. jcsd
  3. Jun 5, 2010 #2


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    The phrase "light year" is the distance it takes light to travel in one year. If an event occurs 100 ly away, it will take 100 years for the light to reach us. The strength of the telescope has nothing to do with it.
  4. Jun 5, 2010 #3
    Yeah, the strength of the telescope mostly refers to how small a spot it can zoom up into your vision field.
  5. Jun 5, 2010 #4
    The only way to see this explosion happen any sooner would involve some means that currently violate the known and a little more understood laws of physics (i.e superseding the speed of light, wormhole, traveling in hyperspace yada yada, basically things that sound cool but are currently far from our technological and/or theoretical means)... as far as i know
  6. Jun 6, 2010 #5


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    100 light years is 100 years in light travel time. It is the least amount of time necessary for a photon to reach us from a distance of 100 light years. A bigger telescope will gather more of these photons, but, not sooner. If the sun went nova 'right now', we would not notice for about 8 minutes. Not to worry, the sun is not a risk to go 'nova'. It will, however, eventually swell up like a toad and become a red giant [in about 4 billion years].
  7. Jun 6, 2010 #6
    If you were to move closer to the explosion you would see the explosion sooner than people on Earth would.

    Although, there is always the concept of jumping particles. I could be wrong, but if you don't observe a particle, all information gathered seems to make it seem as if it jumps. So If you are looking for the explosion, it will take 100 years to reach you. But if you turn around and do something else, thus not observing the light, the light from the explosion will be right behind you.

    Like from the movie, Event Horizon. The shortest distance between two points is zero.
  8. Jun 9, 2010 #7
    Understood. Thank you guys.
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